1. Field
This invention relates to roofing construction and is specifically directed towards the application of hot asphalt compositions to roofs. It provides an apparatus especially adapted to apply hot asphalt uniformly in a selected quantity per unit area to a roof surface.
2. State of the Art
It is conventional practice to apply various roofing compositions in heated liquid form to roof surfaces. These compositions may contain tar, pitch and various asphaltic and/or bituminous components and are commonly referred to as "hot stuff" or "asphalt". The application of hot liquid asphalt to roof surfaces is a time consuming and labor intensive process. It is typically necessary to transfer materials from a source (such as a kettle), usually located on the ground, to an elevated position on the roof. It is not practical to transport more than limited quantities of the hot liquid material to an application zone on the roof because of the crude equipment available for this purpose, and the necessity for keeping the main portion of the material heated. Usual practice is to pour a quantity of hot asphalt onto the roof surface and then to spread it manually with mops and/or rakes. Hot material may be transferred from a kettle on the ground to the roof in a carrier, and then from the carrier to an application zone in a bucket. It is important that the asphalt material be spread uniformly, especially when it is used as a binder for rolled materials, such as roofing felt. Moreover, it is economically important that a sufficient, but not excessive, amount of asphalt material be applied to meet minimum specifications without undue waste. The techniques of the prior art have been inadequate from the standpoint of the efficient use of both labor and material.
Certain suggestions have been made concerning the applying and spreading of hot asphalt on a roof surface through the use of mechanical devices. An example of such a device is the chainlink roofing mop disclosed by U.S. Pat. No. 3,087,118. Although such devices should constitute a major improvement over the simple mops and rakes conventionally employed for this purpose, they nevertheless have been incapable of providing a well-metered, even distribution of "hot stuff" to a roof surface. Other liquid materials, such as waxes, have been applied to floor surfaces by means of mechanical applicators, such as the wax applicator disclosed by U.S. Pat. No. 2,877,476. Such devices are not well suited for the handling of hot liquid asphalt materials, however.